Rookie mistake

I think I made a rookie mistake and need some advice. I left the building permit (what the inspector signs off on) at the house we are rehabbing and now its gone. I've looked everywhere for it and can't find it. I've asked all of my contractors and no one has seen it. What do I do, I'm assuming I need to go talk to the city building department on Monday. Anyone have experience with this and what do they typically do? I am hoping the city keeps track of the progress and what they have signed off on.

The inspector should have filed all paperwork back at the permit/building department, and they should be able to issue you a new permit. While they may act like they're not happy about it, I promise you this isn't the first time it's happened and they have procedures in place to ensure that your project isn't screwed.